Incandescent electric lamp



(No Model.)

B. H. PIPFARD. INOANDESCENT ELECTRIC LAMP.

NU. MLQSZ. Patentefi Feb. 2, 1892.

Fig.2

, thin diculty by employing poreelninlnmprrnn STAT S PATENT OFFICE.

DAVID H. PIFFARD, OF PIFFARD, NE? YORK.

BNCAN ESC-ENT ELECTRIC LAMP.

' a n GATIQM forming part of letters Patent No. 467,982, dated February 2, 1852.

Application filed Key 26, 1891. Serial H0. 994,191. (Ho model.)

1'0 all whom it may concern: Be it known lhnt I, DAVID i-l. PIFFARD, a citizen of. the United Stntes, end a resident of Pimnrd, in the county of Liviugston'alnd'Stnte of New York, have invented it cerinin-new and useful incandescent Electric 'Lnmp, of which thetollowing is n speei'tien. My invention relates-to it means whereby the pnrts through which connection is made between the lump end supply-wire may be protected from deimage end liehility to'ehort circuits when the lump is employed in situations where it is enpoeed to moisture and acid or other fumes lendingto attach the parts and form ehort circuite, in dye-houses, chemice1-- wot-he, colt-works, doc. in these sit-notions the ordinnry metnllic holders for inenndes cent lemps soonheoome useless and the penetrntion of moisture to the interned parts through which connection is mode from the supply-wires to the lump will in time form a. short circuit-end render the devices useless." Attempts hove hitherto been needle to avoid holders, within which thecontn/cts of the lamp holder are mounted and ling the supplyconductore into enid holder. The devices heretofore employed for this pn rpose fnil'to entirely overcome the dimcnlty, as there is an oprtunity for the entrance or moisture nround the lump itself, end, besides, the devices themselvee ere expensive.

The object ot' my invention is to render the employment of such holdingdevi nn'necee enry end to ncooniplieh the some code "in e. cheep, eliicient, end. durn lole wny. To this end i propose to connect the cup lyconductore to the lending-wires in nny esired manner, either through suitehle contuct plntes or hlochn or by twisting the wires together, and to apply to the lnmp-wires. end lump-neck end the snpply-conductore n enth or mass of n eolid non-conducting moisture-proof cement, which isof uproperchnrncter to remain solid and form n g jointnt nil temperntures' to which the lump may be exposed during use or underthe hentingeffectsoi the lump itself, and will further firmly adhere to the glass of the lnnip-glohe end to the eupply-conductors, so to form n solid tight moisture-proof seal or joint nt such points, and thereby prevent the entrnnce of moisture or vnpors which would attack the connections, or by lodging in thematerials surrounding the lamp-wires form a; short circuit between them. The adheringsheath or envelope is preferably put into placeby casting ltaro'und the parts, which 7 may be readily done by applying a mold or shell of more or less -perman ent character around the parts and then pouring in the in- 'sulatinlg sealing substancein ii'heatod'or fiuid state, the su hstnnce being of proper character to solidify as it becomes cool. The exterior sheath or mold might be simply a piece of paiper or cardboard which could be removed after the application ofthe sealinginsnlating substance, or it might be a piece of hard rubher or other suitable material, which would serve as a permanent protective sheath to prevent the breaking away of the insulating mass. When, however, it mixes of insulating substance consisting of the composition invented by me, and hereinafter described; is

employed, the exterior protective sheath is not necessary;

'l'amnwnre that it has been heretofore proposed to envelop the lamp-wires'at the neck of the lamp in a, mass of ples'ter-ot-parimbm such substance would been'tlrely unsuited to the purposes of my invention, as it wouldnot be practically moisture proof in the situ'ntionsnamed. 1- am also aware that it has been proposed to employ a layer of pitch in combination with a. layer of 'plaster-of-paris superposed upon it and a final layer of pitch; but such substance does not answer the purposee oi. my invention because it will not re main solid under t-he temperatures towhich chimp is ordinarily exposed in dyehouses, salt-works, &c.-, and would in any event-become coil; or semi-fluid under the hosting offectsof the lamp itself while in use, so that the insulating moisture-proof substance, such as thepitch, would, if the lnrnpwere inverted in position,-me displaced.

The substance employed must be some material which will adhere to the-glass of the lamp to form n tight joint and will itself not absorb moisture or fumes, and will also not lie-readily attacked by acids. It must alsobe an insulating snbstance'which will not become soft or semi-fluid under the effects of ordinary temperatures, such as it would be exposed to in the ordinary use of the lamp.

In the accompanying drawings, Figure 1 shows in vertical central section a constructlon embodying my invention. Fig. .3 is a similar view of a modification.

B indicates the globe of an incandescent lamp, usually made of glass, and Atlie incandescent filament.

C C are the lamp-wires, which pass through the neck of the lamp in the ordinary way, and D D are supply-wires, preferably having an insulating cover or jacket and connected to the lamp-wires in any proper manner at E- E.

The connection here shown is made by twisting the free ends of the lamp-wires around the bared ends of the lamp-conductors.

H indicates the insulating enveloping mass of non-conducting substance, which seals the parts efltectually against injury and against the formation of short circuits by making aclose moisture-proof joint or seal with the material of the globe of the lamp and with the supply-wires D D at the points I) a, re-

This mass of sealing non-con-f .also necessary that'the material should be such that in cooling it will not draw away or eform an opening at the point of contact with the globe of the lamp. This necessitates the use of some material which will have about the same rate of expansion or contraction of glass when heated.

The substance which I prefer to employ is a compound of rubber, resin, and plaster-ofparis, combined in the proportions of five pounds of rubber-to twenty-four of resin and twenty-six of plasterot-paris,or thereabont,

as described in another'applicati'on for patent filed by me of even date herewith. The rub her and the resin are combined bymelting them together and mixing and preferably allowing the heating to go on for a sufficient length of time to drive off themore readily volatilizable materials in the resin. The plaster-of-paris, dry, is then mixed with the other two ingredients thoroughly, and the compound while' in a heated softened condition is poured into the mold,as already explained. This substance possesses the additional adis also not acted upon by moisture and very little by such strong acids as sulphuric acid, muriatic acid, &c.

It will be seen that the connections from the lamp-wires to the lamp-filament are effectually sealed against entrance of moisture or deleterious vapors and that the seal can be readily and cheaply applied.

A mold of paper applied over the parts can be used in casting the sealing substance around the point of connection of the lampwires and supply-wires I). It sometimes may be desirable to employ a sheath or mold I, such as indicated in Fig. 2, composed ofhard rubber and made sufiiciently thick to form a practically permanent base or neck, which may serve likewise as a handle.

The insulatingsubstance may be applied at the time of the attachment of the lamp to the supply-wires by the user,

\Vhat I claim as my invention is- 1. The combination, with an electric lamp and supply-conductors connected to the lam pwires, of a solid homogeneous sheath or envelope of an adherent non-conducting moisture-proof cement cast around said lamp wires and conductors and adapted to form a tight moisture-proof joint ,both with the glass of the lamp and the said conductors to adhere to the glass and to the conductors and to remain solid under the temperatures to which it is exposed while the lamp is in use.

2. The combination, with an electric lamp and the insulated supply-conductors having their bared ends connected to the lamp-wires,;.

of an unbroken or homogeneous solid envel- 5 oping mass of non-conducting material ail-.-

hering to and forming a tight moisture-proof joint with the lamp casing or globe and with the insulated conductors above the point of attachment to the lamp-wires, said sealing or cementing substance being of proper character, as described, not to become soft or semi-' 7 'fiuid except at a higher temperature than that to which it is exposed by the heating of the lamp'and lamp-conductors or of the atmosphere in the place where it is used.

Signed at Geneseo, in the county of Livingston and State of New York, this 20th day 1 of May, A. D. 1891.

DAVID II. IIFFARI). Witnesses:

Gno. B. ADAMS, RoBT. .LAUDERDALE. 

